Abstract：Satellite remote sensing images provide factual image evidence in tracing faults that cut through the ground surface. This facilitates evaluation on the extent of the fault，since the fault trace can be directly read from the images. A three-dimensional computation model is employed，which is constructed from DTM data，with satellite image mapping on it. By the image-enhancing procedure of simulating different light projecting direction and locating position by computer，the invisible fault trace can be easily identified. Furthermore，if the image indicates that the fault scarp cuts through a set of river terraces or recent fluvial deposit，the activity of the fault can be determined. Two cases，Chelungpu Fault and Hsinchang Fault，are discussed. These case studies shows that the satellite image-enhancing procedure is very useful for the fault activity study，especially in the plain area. It can improve the fault trace features and provide direct image evidence regarding the fault activity to the researcher. In the case of Chelungpu Fault，the big earthquake occurred 3 years after our active fault confirmation report，proved our study. In addition，if the map of the fault trace by satellite image is superposed on that of the recent earthquake rupture，these two traces almost cover each other in the research area.
2004, Vol. 23 
